JPH10246978A - Electrophotographic photoreceptor, process cartridge with the same, and electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve mechanical strength such as wear and scuffing resistances without deteriorating electrophotographic characteristics and to ensure superior durability, by incorporating a polycarbonate polymer having a graft structure formed by polymerizing a silicon-contg. vinyl monomer to specified hydrocarbon groups into the surface layer of a photosensitive layer. SOLUTION: This electrophotographic photoreceptor has a photosensitive layer on the electrically conductive substrate and contains a polycarbonate polymer having a graft structure formed by polymerizing a silicon-contg. vinyl monomer to the monovalent aliphatic unsatd. hydrocarbon groups of polycarbonate represented by the formula in the surface layer of the photosensitive layer. In the formula, each of R1 and R2 is H, an alkyl, etc., each of R3 and R4 is H, an alkyl, aryl, etc., at least one of R3 and R4 is a 2-8C aliphatic unsatd. hydrocarbon, each of X1 and X2 is a single bond, -O-, -S-, etc., and each of (m) and (n) is the number of repeating units.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member, a process cartridge having the electrophotographic photosensitive member, and an electrophotographic apparatus.

[0002]

2. Description of the Related Art Inorganic photoconductive materials such as zinc oxide, selenium and cadmium sulfide are known as photoconductive materials used for electrophotographic photoreceptors, but polyvinyl carbazole and organic photoconductive materials are known as organic photoconductive materials. Phthalocyanine, azo pigments, etc. are attracting attention for their advantages such as high productivity and no pollution.
Although it has a disadvantage inferior in durability and the like, it has come to be widely used. Recently, new materials have also been proposed in which the above-mentioned disadvantages have also been improved, and in particular, the photoconductive properties are surpassing those of the inorganic photoconductive materials.

An electrophotographic photosensitive member is repeatedly subjected to actions such as charging, exposure, development, transfer, cleaning, and static elimination in an electrophotographic process in a copying machine, a laser beam printer, and the like. Various durability is required. In particular, mechanical strength such as wear resistance and scratch resistance is the largest factor that determines the durability life.

On the other hand, since the organic photoconductive material does not have a film forming property by itself, it is generally formed with a binder resin. Therefore, it is not an exaggeration to say that abrasion resistance and scratch resistance are almost determined by the choice of binder resin. However, the binder that satisfies the photoconductive property is considerably limited, and the abrasion resistance is far lower than that of the inorganic electrophotographic photosensitive member.

The electrophotographic process that is most involved in abrasion resistance is cleaning. In recent years, with the degree of atomization of the developer, the cleaning has been required to have higher and higher precision.
In addition, it is advantageous to employ blade cleaning in order to realize a simpler device configuration as the space of the device is reduced. Blade cleaning employs a simple structure in which an elastic member such as a plate-like polyurethane is pressed against the photoreceptor in the generatrix direction. However, in this case, a large frictional force is generated between the photoreceptor and the blade, which promotes abrasion of the photoreceptor and lowers durability.

In order to cope with this, it is effective to give the photoreceptor a strength capable of withstanding a frictional force. Generally, the binder resin is made to have a high molecular weight, and a curable binder resin is used. However, the high molecular weight binder resin causes a thickening of the coating paint in a coating process which is a main production process of the organic photoreceptor, and therefore, there is a limit in increasing the molecular weight. Further, the curable binder resin does not have sufficient photoconductivity due to the reaction deterioration of the organic photoconductive material at the time of curing, the formation of impurity levels due to unreacted functional groups and polymerization initiator by-products, and the like. .

[0007] It is also effective to impart a lubricating property to the electrophotographic photosensitive member, but there is no material which is compatible with film forming property and compatibility.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic photoreceptor which has improved mechanical strength such as abrasion resistance and scratch resistance without deteriorating electrophotographic characteristics and has excellent durability. It is to be. Another object of the present invention is to provide a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.

[0009]

According to the present invention, there is provided an electrophotographic photosensitive member having a photosensitive layer on a conductive support, wherein a surface layer of the photosensitive layer has at least a polycarbonate represented by the following general formula (1).
An electrophotographic photoreceptor characterized by containing a polycarbonate polymer having a graft structure obtained by polymerizing a silicon-containing vinyl monomer on a monovalent aliphatic unsaturated hydrocarbon group of a carbonate. . General formula

Embedded image In the formula, R ₁ and R ₂ each independently represent a hydrogen atom, an alkyl group, a halogen atom, a cycloalkyl group or an aryl group, and R ₃ and R _{4 each} have at least one having 2 carbon atoms.
To 8 are each independently a hydrogen atom, an alkyl group, a halogen atom, a cycloalkyl group or an aryl group; X ₁ and X ₂ are each independently a single atom; Bond, -O-, -S-, -SO-, -S
O _2- , An aryl group, a halogen-substituted alkyl group or a halogen-substituted aryl group), Further, m and n indicate the number of repeating units, and the repeating ratio of (A) and (B) is 0.01 ≦ (B) / weight ratio.
{(A) + (B)} ≦ 0.3.

As the silicon-containing vinyl monomer, those having a structure represented by the following general formula (2) or (3) are particularly preferable. General formula

Embedded image General formula

Embedded image In the formula, Y represents an alkylene group or an arylene group;
₅ is a hydrogen atom or a methyl group; R _{6 to} R ₁₀ are each independently a hydrogen atom, a halogen atom, an alkyl group, an aryl group or an alkoxy group, and p and q are integers of 0 to 5.

According to the present invention, there is further provided an electrophotographic photoreceptor of the present invention, and at least one means selected from the group consisting of a charging means, a developing means and a cleaning means, integrally supported on the electrophotographic apparatus main body. It is composed of a process cartridge characterized by being detachable.

Further, the present invention comprises an electrophotographic apparatus comprising the electrophotographic photosensitive member of the present invention, a charging unit, an image exposing unit, a developing unit and a transferring unit.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The characteristics of the polycarbonate polymer used in the present invention are that the main chain has a polycarbonate skeleton, so that the film has good film-forming properties and the silicon-containing vinyl monomer is added to the side chain. Due to the polymerization, the surface energy after film formation is extremely small, and since it is grafted to the main chain, there is no bleeding to the surface, and this effect is uniformly obtained over the entire formed resin layer. It is to be demonstrated.

Therefore, by using the polycarbonate polymer used in the present invention as a binder for the surface layer, a photoreceptor surface having a low surface energy can be obtained continuously, and toner, Abrasion and damage of the surface of the photosensitive member caused by the direct load of the paper, the cleaning member and the like are suppressed, and a highly durable electrophotographic photosensitive member can be obtained.

Tables 1 to 6 show specific examples of the structure of the polycarbonate represented by the general formula (1) and the silicon-containing vinyl monomer, but the present invention is not limited thereto.

In the general formula (1), examples of (A) (structural examples 1 to 5)
17)

[Table 1]

[Table 2]

In the general formula (1), examples of (B) (Structure Example 18)
~ 23)

[Table 3]

Structural examples of silicon-containing vinyl monomers (Structure examples 24-33)

[Table 4]

[Table 5]

[Table 6]

The polycarbonate represented by the general formula (1) is
Known methods (Polycarbonate resin handbook, 19
August 28, 1992, First Edition, First Edition, Published by Nikkan Kogyo Shimbun
3 to 18), the corresponding bispheno-
Synthesized from a class of compounds.

The polymerization of the silicon-containing vinyl monomer can be easily obtained by heating the reaction system in the presence of a radical initiator in the polycarbonate represented by the general formula (1). It is preferable to carry out the solution polymerization in which the carbonate is dissolved in an organic solvent.

Polycarbonate used in the present invention
The polymer can be used alone as a binder resin, or can be used as a mixture with another resin. Mixable resins include polyester, polyurethane,
Polyarylate, polyethylene, polystyrene, polybutadiene, polycarbonate, polyamide, polypropylene, polyimide, polyamideimide, polysulfone,
Examples include polyallyl ether, polyacetal, nylon, phenolic resin, acrylic resin, silicone resin, epoxy resin, allyl resin, alkyd resin, and butyral resin. Further, reactive epoxy, (meth) acrylic monomers and oligomers can be mixed.

The photosensitive layer of the electrophotographic photosensitive member of the present invention has a single layer or a laminated structure. In the case of a single-layer structure, the generation and transfer of the photocarriers are performed in the same layer, and the polycarbonate having the terminal structure is contained in this layer. In the case of a stacked structure, a charge generation layer that generates photocarriers and a charge transport layer in which carriers move are stacked. The surface layer may be formed on either the charge generation layer or the charge transport layer. The polycarbonate having the terminal structure is contained in the layer forming the surface layer.

In the case of a single-layer photoreceptor, the thickness of the photosensitive layer is 5 to 10
0 μm, preferably 10 to 60 μm. 20 to 80%, preferably 30 to 7% of the charge generation material and the charge transport material
It contains 0%.

In the case of a laminated photoreceptor, the thickness of the charge generation layer is 0.1 mm.
It is 001 to 6 μm, preferably 0.01 to 2 μm.
The amount of the charge generating material is 10 to 100%, preferably 40 to 100%.
100%. The thickness of the charge transport layer is 5 to 100 μm,
Preferably it is 10 to 60 μm. The amount of charge transport material is 20-80%, preferably 30-70%.

Examples of the charge generating material include phthalocyanine pigments, polycyclic quinone pigments, azo pigments, perylene pigments, indigo pigments, quinacridone pigments, azurenium salt pigments, squarylium dyes, cyanine dyes, pyrylium dyes, thiopyrylium dyes, xanthene dyes, and quinone imine dyes. ,
Examples include triphenylmethane dye, styryl dye, selenium, tellurium, amorphous silicon, cadmium sulfide and the like.

Examples of the charge transport material include pyrene compounds, carbazole compounds, hydrazone compounds, N, N-dialkylaniline compounds, diphenylamine compounds, triphenylmethane compounds, pyrazoline compounds, styryl compounds, stilbene compounds and the like.

In the electrophotographic photosensitive member of the present invention, a protective layer may be laminated on the photosensitive layer. In this case, the polycarbonate having the terminal structure is also contained in the protective layer. The thickness of the protective layer is 0.01 to 20 μm, preferably 0.1 to 10 μm. The protective layer may contain the above-described charge generation material or charge transport material, a metal and its oxides, nitrides, salts, alloys, and conductive materials such as carbon.

As the conductive support used in the electrophotographic photoreceptor of the present invention, iron, copper, nickel, aluminum,
Titanium, tin, antimony, indium, lead, zinc,
Metals and alloys, such as gold and silver, or oxides and cars thereof
And a conductive resin and the like, and the shape includes a cylindrical shape, a belt shape, and a sheet shape.

The above-mentioned conductive material may be molded, but may be applied as a paint or may be deposited.

An undercoat layer may be provided between the conductive support and the photosensitive layer. The undercoat layer is mainly composed of a binder resin, but may contain the conductive material or the acceptor.
As the binder resin for forming the undercoat layer, polyester, polyurethane, polyarylate, polyethylene,
Polystyrene, polybutadiene, polycarbonate, polyamide, polypropylene, polyimide, polyamide imide, polysulfone, polyallyl ether, polyacetal, nylon, phenolic resin, acrylic resin, silicone resin, epoxy resin, urea resin, Allyl resin,
Alkyd resin, butyral resin and the like can be mentioned.

For the preparation of the electrophotographic photoreceptor of the present invention, vapor deposition,
A method such as coating is used. For the coating, means such as bar coater, knife coater, roll coater, attritor, spray, dip coating, electrostatic coating, powder coating and the like are used.

Next, the process cartridge and the electrophotographic apparatus of the present invention will be described. FIG. 1 shows a schematic configuration of an electrophotographic apparatus having a process cartridge having an electrophotographic photosensitive member of the present invention. In the figure, reference numeral 1 denotes a drum-shaped electrophotographic photoreceptor of the present invention, which is driven to rotate at a predetermined peripheral speed in the direction of an arrow around a flick 2. In the course of rotation, the photosensitive member 1 is uniformly charged at a predetermined positive or negative potential on its peripheral surface by the primary charging means 3 and then exposed to image exposure means (such as slit exposure or laser beam scanning exposure). Shown)
Receives image exposure light 4 from. Thus, an electrostatic latent image is sequentially formed on the peripheral surface of the photoconductor 1.

The formed electrostatic latent image is then developed.
Is transferred to the transfer material 6 from the paper supply unit (not shown) and fed between the photosensitive member 1 and the transfer means 6 in synchronization with the rotation of the photosensitive member 1. Are sequentially transferred by the transfer means 6. The transfer material 7 having undergone the image transfer is separated from the photoreceptor surface, introduced into the image fixing means 8 and subjected to image fixing, thereby being printed out as a copy (copy) outside the apparatus. The surface of the photoreceptor 1 after the image transfer is cleaned and cleaned by removing the transfer residual toner by the cleaning means 9, and further subjected to a static elimination process by the pre-exposure light 10 from the pre-exposure means (not shown). After that, it is repeatedly used for image formation. When the primary charging means 3 is a contact charging means using a charging roller or the like, pre-exposure is not necessarily required.

In the present invention, a plurality of components such as the photosensitive member 1, the primary charging means 3, the developing means 5 and the cleaning means 9 are integrally connected as a process cartridge. Alternatively, the process cartridge may be configured to be detachable from a main body of an electrophotographic apparatus such as a copying machine or a laser beam printer. For example, at least one of the primary charging means 3, the developing means 5 and the cleaning means 9 is integrally supported together with the photoreceptor 1 to form a cartridge, and the apparatus main body is guided by a guide means such as the rail 12 of the apparatus main body. The process cartridge 11 can be detachably mounted on the cartridge. When the electrophotographic apparatus is a copier or a printer, the image exposure light 4 uses reflected light or transmitted light from the original, or reads the original with a sensor and converts it into a signal. This is light emitted by scanning of the laser beam, driving of the LED array, driving of the liquid crystal shutter array, and the like.

[0035]

【Example】

Example 1 Synthesis of polycarbonate of general formula (1) 3,3'-diallylbisphenol A (20 g) and bisphenol Z (80 g) were prepared by using a stirrer, a thermometer, a gas inlet tube and a reflux condenser equipped with a stirrer. In a one-necked round-bottomed flask, dry nitrogen gas was introduced while flowing, and an aqueous 8% sodium hydroxide solution 55
0 ml, 400 ml of methylene chloride, 0.8 g of p-nonylphenol as a terminator and 3 ml of a 10% aqueous solution of triethylamine as a catalyst were introduced. A polycondensation reaction was performed by blowing phosgene gas. After completion of the reaction, methylene chloride, 100
0 ml was added for dilution, washed with water, dilute hydrochloric acid and water in that order, and then poured into methanol to obtain polycarbonate.
A polymer was obtained. As a result of measuring the obtained polycarbonate,

Embedded image It was confirmed that (A) :( B) was a copolymer having a weight ratio of 0.8: 0.2.

Polymerization of Silicon-Containing Vinyl Monomer Next, 80 g of the polycarbonate obtained above and 0.5 g of azobisisobutyronitrile as a radical initiator were used.
Was dissolved in 1000 liters of chlorobenzene, and
Of the silicon-containing vinyl monomer (R: -C
H ₃ , k = 10) into a three-necked round bottom flask equipped with a stirrer, a thermometer, a gas inlet tube and a reflux condenser together with 20 g, and allowed to react at a temperature of 80 ° C. for 1 hour while flowing dry nitrogen gas. went. After cooling, the polymer was dropped into 1 liter of methanol to reprecipitate the polymer, washed and dried, and then a polycarbonate polymer 96 obtained by polymerizing a silicon-containing vinyl monomer.
g was obtained. This is designated as Sample 1.

Preparation of Electrophotographic Photoreceptor 10 parts of methoxymethylated nylon (parts by weight, hereinafter the same)
And 150 parts of isopropanol were mixed and dissolved, and then an aluminum cylinder having an outer diameter of 80 mm and a length of 360 mm was used.
By dip coating to form an undercoat layer having a thickness of 1 μm.

Next, 10 parts of the following azo pigments:

Embedded image Polycarbonate (bisphenol A type, molecular weight 30,000)
5 parts and 700 parts of cyclohexanone were dispersed in a sand mill, and this dispersion was applied by dip coating on the undercoat layer to form a charge generation layer having a thickness of 0.05 μm.

Next, 10 parts of the following triphenylamine:

Embedded image After 7 parts of the sample 1, 150 parts of chlorobenzene and 100 parts of dichloromethane were dissolved and mixed, this solution was applied onto the charge generating layer by dip coating, dried with hot air, and formed into a 20 μm-thick charge transport layer. A photoreceptor was made.

COMPARATIVE EXAMPLE 1 Polycarbonate in which a silicon-containing vinyl monomer was not polymerized (described above) alone was used as the binder resin for the charge transport layer, and no polycarbonate having a terminal structure was used. In the same manner as in Example 1, an electrophotographic photosensitive member was prepared.

The following comparative tests were performed on the electrophotographic photosensitive member prepared in Example 1 and the electrophotographic photosensitive member prepared in Comparative Example 1.

Abrasion Resistance Test The electrophotographic photosensitive member was subjected to a wear test at a load of 500 g (two pieces) for 5000 cycles using a taper type abrasion tester. The weight loss due to abrasion was about 20% less in the electrophotographic photoreceptor of Comparative Example 1 than in the electrophotographic photoreceptor of Example 1, and the polycarbonate obtained by polymerizing a silicon-containing vinyl monomer was used.
The effect of using the polymer was confirmed.

Contact Angle The contact angle with water was compared by a drop-type contact angle meter. As a result, the contact angle of the electrophotographic photosensitive member of Example 1 was as large as 106 degrees, while that of the electrophotographic photosensitive member of Comparative Example 1 was as small as 81 degrees.

Endurance on Actual Machine Each of the above electrophotographic photosensitive members was set in a copying machine (trade name: CLC500, manufactured by Canon Inc.), and 20,000 sheets were subjected to endurance. In the electrophotographic photosensitive member of Comparative Example 1, white image fogging became remarkable at 13,000 sheets, and the electrophotographic photosensitive member of Example 1 was unusable. there were. Further, the shaving amount of the photoreceptor after the endurance was about 25% smaller than that of the electrophotographic photoreceptor of Comparative Example 1.

Examples 2-6 Various silicon-containing vinyl monomers were prepared in the same manner as in Example 1.
Was polymerized to synthesize a polycarbonate polymer. Table 7
And 8 show the structure.

Using these polycarbonate polymers,
Electrophotographic photosensitive members corresponding to Examples 2 to 6 were prepared in the same manner as in Example 1. Evaluation was performed in the same manner as in Example 1.
Table 9 shows the results.

Comparative Examples 2 to 6 Comparative Examples 2 to 6 were carried out in the same manner as in Example 1 except that a polycarbonate in which a silicon-containing vinyl monomer was not polymerized was used.
Each electrophotographic photosensitive member corresponding to was prepared. Evaluation was performed in the same manner as in Example 1. Table 9 shows the results.

[0048]

[Table 7]

[Table 8]

[0049]

[Table 9]

[0050]

The electrophotographic photoreceptor of the present invention has improved abrasion resistance and excellent durability by incorporating a polycarbonate polymer obtained by graft-polymerizing a silicon-containing vinyl monomer into a surface layer. It has a remarkable effect. Also,
In a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member, a remarkable effect is similarly exhibited.

[Brief description of the drawings]

FIG. 1 is a process car having an electrophotographic photoreceptor of the present invention.
FIG. 2 is a diagram illustrating a schematic configuration of an electrophotographic apparatus having a cartridge.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrophotographic photoreceptor of the present invention 2 axis 3 Primary charging means 4 Image exposure light 5 Developing means 6 Transfer means 7 Transfer material 8 Image fixing means 9 Cleaning means 10 Pre-exposure light 11 Process cartridge 12 Rail

Claims (5)

[Claims] 1. An electrophotographic photoreceptor having a photosensitive layer on a conductive support, wherein the surface layer of the photosensitive layer has at least monovalent aliphatic unsaturation of a polycarbonate represented by the following general formula (1). 1. An electrophotographic photoreceptor comprising a polycarbonate polymer having a graft structure in which a silicon-containing vinyl monomer is polymerized on a hydrocarbon group. General formula In the formula, R ₁ and R ₂ each independently represent a hydrogen atom, an alkyl group, a halogen atom, a cycloalkyl group or an aryl group, and R ₃ and R _{4 each} have at least one having 2 carbon atoms.
To 8 are each independently a hydrogen atom, an alkyl group, a halogen atom, a cycloalkyl group or an aryl group; X ₁ and X ₂ are each independently a single atom; Bond, -O-, -S-, -SO-, -S
O _2- , An aryl group, a halogen-substituted alkyl group or a halogen-substituted aryl group), Further, m and n indicate the number of repeating units, and the repeating ratio of (A) and (B) is 0.01 ≦ (B) / weight ratio.
{(A) + (B)} ≦ 0.3. 2. The electrophotographic photoreceptor according to claim 1, wherein said silicon-containing vinyl monomer has a structure represented by the following general formula (2). General formula In the formula, Y represents an alkylene group or an arylene group;
₅ is a hydrogen atom or a methyl group; R _{6 to} R ₁₀ are each independently a hydrogen atom, a halogen atom, an alkyl group, an aryl group or an alkoxy group, and p and q are integers of 0 to 5. 3. The electrophotographic photoreceptor according to claim 1, wherein said silicon-containing vinyl monomer has a structure represented by the following general formula (3). General formula In the formula, Y represents an alkylene group or an arylene group;
₅ is a hydrogen atom or a methyl group; R _{6 to} R ₁₀ are each independently a hydrogen atom, a halogen atom, an alkyl group, an aryl group or an alkoxy group, and q is an integer of 0 to 5. 4. The electrophotographic photosensitive member according to claim 1, and at least one means selected from the group consisting of a charging means, a developing means and a cleaning means are integrally supported, and are detachably attached to an electrophotographic apparatus main body. A process cartridge characterized by the following. 5. An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1, a charging unit, an image exposing unit, a developing unit, and a transferring unit.